R., P.K., Ratnam, P.K., R., P.K.K. and K., K.K.T.V. 2020. Clinical profile of patients with chronic obstructive pulmonary disease at a tertiary care hospital. International Journal of Advances in Medicine. 7, 3 (Feb. 2020), 426–430. DOI:https://doi.org/10.18203/2349-3933.ijam20200652.